The present invention relates to a load feeder for switching and protecting a load that can be connected in a main power circuit for voltages above 100 volts. The present invention includes a feeder assembly and a support part having first plug connections for connection to a power bus with main power cables, a data bus and, if required, an auxiliary power bus. The feeder assembly can be mechanically adapted on the support part and can make contact with the first plug connections via first mating plug connections.
A load feeder of this generic type is described in European Patent No. 0753916. The main power cables, the data bus and the auxiliary power bus in this case are routed as a busbar in the bottom part of the load feeder, once this has been installed in the cubicle. This means that, for installation, it must be clear from the start which switching devices must be provided at what point in the cubicle. The conventional busbar adapter system is used for connection of a motor feeder and has, on its upper face, top-hat section rails onto which a contactor and a power breaker can be snapped.
A switchgear unit with a communications capability is described PCT Application No. WO 96/42188 which, for a cubicle with a data bus, provides simple adaptation and contact-making for switching devices in conjunction with electronics that are required for data communication. The switchgear unit includes an equipment base on which a plurality of switching devices can be adapted via a standard profiled rail, as well as a communications unit, which is held on the equipment base and has plug contacts via which the electrical drive for the switching devices is provided. The switchgear unit may include, for example, a contactor and a power breaker. If another switching device is required, the equipment base is expanded by one equipment base expansion part. Main power connections for connection to a three-phase busbar system are provided on the rear wall of the equipment base of the switchgear unit. The switchgear unit is at the same time held and made contact with by hooking it on the busbars. The data is transferred to the electronics in the communications module via a bus connector or by insulation-piercing contacts on a bus cable, directly at the communications module.
In the case of automation devices, European Patent No. 0236711 described in detail the use of input/output assemblies for adaptation. The input/output assembles be snapped onto mounting rails and can connected to one another via additional control cables. In this case, the mounting racks are designed individually as modular mounting racks having a matching circuit.
A connecting block for the external wiring is mechanically connected to the mounting rack. The connecting block and the mounting rack can be connected via a plug connection to the individual assemblies.
The matching circuit in this case is in the form of a circuit board in the mounting rack. There are female connector strips on the circuit board, for connection to plug connections on the input/output assemblies. A male connector strip is used to connect the modular mounting racks to one another and, connected to the circuit board, is connected to a ribbon cable which, for its part, a female connector strip is connected. The electrical connection from the male connector strip of the adjacent mounting rack can be made via this female connector strip.
The mounting racks can be connected to one another side by side by hooking tabs, which project at the sides, into recesses, which are designed in a matching manner in the enclosures of the mounting racks. The electrical connection is made independently of this.
German Patent Application No. 197 34 709.6, which has not been published yet, discloses a switchgear system with a power bus of modular construction. In this case, a plurality of switching devices are operated via the same power supply. To this end, each switching device has an associated power bus module, which in each case has a power bus section via which the associated switching device can be electrically connected to the power supply. In this case, the power bus sections are connected to one another to form a continuous distribution rail. The power feeder can be connected at least to one of the power bus sections.
An object of the present invention is to provide a load feeder, whose installation and test complexity are improved in the context of a construction system, and which offers simple expansion capabilities, with the wiring complexity being reduced.
The object is achieved in that the support part is constructed as a modular first base lower part of a support system that can be expanded in a modular manner, with a cable and bus system in order to form a power, data and auxiliary-power bus, and, for this purpose, first cable and/or bus sections are integrated with associated second plug and mating plug connections in the first base lower part, via which second cable and/or bus sections can make contact via associated third plug and mating plug connections with a correspondingly designed second base lower part in order to expand the support system. The configuration according to the present invention results in the following advantages:
Space reduction in the cubicle
Reduction in the installation, wiring, testing, configuration and servicing cost and complexity.
The solution allows control wiring and power distribution for a remote peripheral and load feeders in one operation. The data bus, auxiliary power bus, power bus and mechanical support unit are combined to form a support system which can be assembled in advance and lengthened as required by arrangement in a row. The input and output assemblies as well as the load feeders may be constructed, configured and operated as equivalent remote peripherals in a row.
An advantageous embodiment of the present invention is achieved if the second plug connections and mating plug connections of the first base lower part make direct contact with the third plug connections and mating plug connections of a second base lower part when the latter is arranged in a row alongside the first base lower part. Contact is in this case made in conjunction with the mechanical coupling of two base lower parts, that is to say in a single operation.
If the second base lower part is part of an input and output assembly, then this allows a feeder to be joined in a simple manner to an input and output assembly in a confined space in the cubicle.
A particularly space-saving arrangement is achieved if the second plug and mating plug connections, which are associated with the first cable and/or bus sections, are provided on side walls of the base lower part.
With regard to the testing and servicing effort being as low as possible, it is advantageous for the base lower part to have a removable power bus module with power bus sections which are located in a main power circuit and via which a load can be connected to the load feeder.
A particularly simple implementation of the data bus is created if this data bus is provided by a printed circuit board having conductor tracks which are combined at one end to form a plug connection and at the other end to form a mating plug connection.
In order to achieve a simple electrical connection between a feeder assembly and the data bus, it is advantageous for a T-functionality for connecting the feeder assembly to the data bus to be produced via a plug connection in conjunction with the conductor tracks on the printed circuit board.
A particularly simple embodiment of the feeder assembly is obtained if this assembly includes a contactor, a power breaker and electronics which convert signals that can be received via the data bus into control signals for the contactor or and/the power breaker and return signals from the contact or power breaker to the data bus.
A further advantageous embodiment is provided if the base lower part has a guide shaft with plug connections for connection to the power bus, and the feeder assembly is provided with an insertion part which can be inserted into the guide shaft, has dimensions which are matched appropriately to this guide shaft and is provided with mating plug connections which make contact with the plug connections of the base lower part for mechanical adaptation of the feeder assembly.